The present invention relates to a breaker apparatus to be used for switching the power cable connected to the battery or the like of the automotive vehicle between the conduction state and the out-of-conduction state.
A breaker apparatus as disclosed in the Unexamined Japanese Patent Application Publication No. Hei 9-223439 is conventionally known as a breaker apparatus of the type described above. This breaker apparatus comprises, as shown in FIG. 14, a breaker switch including a pair of fixed electrodes 5, 5 standing upright on the breaker body 1 and a movable electrode 4 formed on the plug 3 to be fitted to the breaker body for plugging in and out of both fixed electrodes 5, 5, and a fuse 2 provided in series with the breaker switch.
When the plug 3 is pulled out, both fixed electrodes are disconnected so that the fuse 2 can be replaced with the cable e being in the out-of-conduction state, and thereafter when the fuse 2 is replaced and the plug 3 is fitted to the breaker body 1, the movable electrode 4 connects between both fixed electrodes 5, 5 so as to bring the cable e into conduction.
In this stage, it is important to know whether or not the plug 3 is properly fitted, and thus in the related art, a magnet 8 is provided at the prescribed position on the handle 7 to be used for fitting in or pulling out the plug 3 so that when the handle 7 is tilted down after the plug 3 is inserted, a magnet force of the magnet 8 is detected by the sensor (not shown) provided on the breaker body 1, thereby detecting whether or not the plug 3 is correctly fitted. However, detection by a magnetic force is not sufficiently accurate since it may be affected by electrical current or the like around the sensor.
In the conventional breaker apparatus, there is an apprehension that the plug 3 is held only by a frictional force between the movable electrode 4 and the fixed electrodes 5, 5 thereby being poor in retaining force, an apparatus providing a locking mechanism for positively retaining the plug at the fitted position is on the way to development. More specifically, the lock lever is pivotably provided on the plug, and when the lock lever is pivoted into the locking position after the plug is fitted in position, the plug is locked in the retained state together with the lock lever by the locking portion formed on the breaker body.
Whether or not the lock lever is pivoted to the normal locking position is detected by the micro switch, whereby whether or not the plug is correctly fitted can be detected.
An example of the structure described above is schematically shown in FIG. 15. In other words, the lock lever r is supported so as to be able to pivot from the upright position r1, with respect to the plug to the horizontal locking position r2, and when the lock lever r is pivoted into the locking position r2 after it is correctly fitted to the breaker body, the locking end ra, is locked to the locking portion of the breaker body.
On the other hand, the breaker body is provided with a micro switch M in the pivoting area of the detecting end rb of the lock lever r. The micro switch M is known switch having a swinging strip K as an actuator, wherein the swinging strip K is mounted vertically upwardly.
When the lock lever r is pivoted to the locking position r2, the detecting end rb presses the swinging strip K to turn the micro switch ON, and thereby detecting whether or not the lock lever is locked and the plug is correctly fitted, in which accuracy can be expected in comparison with the case using a magnetic force.
The micro switch M described above is turned on when the button or the like is pressed by the movement of the swinging strip K from the natural state by a prescribed angle, and it is preferable that the micro switch M is turned on simultaneously with the arrival of the lock lever r at the locking position r2. However, when considering tolerances of the mounting position of the micros witch M or the locking lever r, a time lag occurs between the timing when the swinging strip K presses the detecting end rb of the locking lever r and the timing when the micro switch is turned on.
Especially, in FIG. 15, when the micro switch M and the lock lever r are positioned at a distance from each other, it is set so that the micro switch M is turned on slightly before the lock lever r reaches the locking position r2 because the condition that the micro switch M is not turned on even in the state where the lock lever r is in the locked state must be avoided.
Therefore, employing a locking lever r having a same width along the whole length thereof allows a timing of pressing the micro switch M to be earlier, and thus not some little process is required until the lock lever r is locked after the micro switch M is turned on. However, there may be cases where the lock lever r is not locked completely because its pivotal movement is interrupted on the way although the micro switch M is turned on and a signal indicating that the locking is complete is obtained, whereby detection of the completion of locking cannot be performed correctly.
As a matter of course, there are some considerable countermeasures such as reducing the width of the lock lever, or changing the mounting position of the locking lever or the micro switch to shift the timing of pressing the swinging strip of the micro switch. However, the former has a limit in the strength, and the latter cannot be employed easily since major design changes are required.
With such conditions in view, an object of the present invention is to provide a system in which detection of the completion of locking can be made correctly while minimizing design changes involved.
In order to achieve the object described above, the first aspect of the present invention is a breaker apparatus comprising: a breaker body, a breaker switch including a pair of fixed electrodes standing upright on the breaker body, a plug detachably mounted on the breaker body, and a movable electrode provided on the plug for disconnecting and connecting between both fixed electrodes by being pulled out or pushed in to the both fixed electrodes; and a fuse mounted in parallel with the breaker switch, characterized in that a locking lever is pivotably mounted on one of the breaker body and the plug and the locking lever is pivoted to the locking position where the plug is locked in the fitted state, in that the breaker body is provided with a micro switch having a swinging strip for detecting whether or not the locking lever is pivoted to the locking position so that the micro switch is activated when the tip of the locking lever pivots along the length of the swinging strip and presses the swinging strip on the way to activate the micro switch, and in that the tip of the locking lever is formed so that the length is maximum at the rear edge that trails when the locking lever is pivoted toward the locking position and decreases gradually toward the leading edge.
The second aspect of the present invention is a breaker apparatus as set forth in the first aspect, characterized in that the locking lever is provided on the plug for serving also as a handle.
When a plug is mounted on the breaker apparatus, both fixed electrodes are brought into conduction via the movable electrode in the plug. When the locking lever is pivoted to the locking position after the plug is correctly fitted, the plug is locked in a retained state. In association with the pivotal movement of the locking lever into a locking position, the tip of the locking lever abuts against the swinging strip and presses the same, and thus the micro switch is activated.
Since the shape of the tip of the locking lever is such that the length is maximum at the rear edge that trails when the locking lever is pivoted to the locking position and reduces gradually toward the leading edge, it presses the swinging strip when it moves closer to the locking position than the case of the conventional case to activate the micro switch.
Referring now to FIG. 11, the effect of the invention will be described while comparing with the conventional apparatus employing a locking lever having a same width along the whole length thereof.
In the same figure, the sign R designates the locking lever of the present invention, and the sign r designates the conventional locking lever, and the micro switch M is turned on when the swinging strip K is pressed by the tip of the locking lever R, r and swung by a prescribed angle from the natural state to the position G. The signs S and s designate centerlines of the width of the locking lever of the present invention and of the conventional locking lever respectively passing through the axis of the pivotal movement thereof, and locking action is completed when the centerlines S and s reach the position C (locking position). At this time, the swinging strip K reaches the position H.
When the locking levers R, r and the micro switch M is disposed at the shortest distance with respect to each other within a tolerance, for example, the conventional locking lever r activates the micro switch M when it reaches the position A. On the other hand, since the tip portion of the locking lever R of the present invention is shaped in such a manner that the trailing edge is the longest and the leading edge forms so called a clearance, the trailing edge of the tip portion presses the swinging strip K by a prescribed angle when the centerline reaches the position B to activate the micro switch.
In other words, according to the present invention, the micro switch M can be activated later than the case of the conventional case by the time period corresponding to the angle between A and B, i.e. at the timing when it is closer to the locking position C than the conventional case. In other words, the difference between the activation of the micro switch M and the arrival of the locking lever R to the locking position C may be reduced so that the completion of locking can be detected correctly.
In addition, it requires only minor design changes such as changing the shape of the tip portion of the locking lever R.
Since fitting locking of the plug can be performed in a series of actions in the state of gripping the locking lever, the workability is improved.